Thanks Greg you make a good point, the loco did a good job, at medium speed, with track that had been in use and was not too badly tarnished. I should have thought about using a very slow speed on the rest of the track.I was interested that the track cleaning loco did not do the trick... often people try to run it too fast and the track is not clean enough to pick up the power the loco needs.
Heavily oxidized track needs it to move very slow, but when I ran mine on DC, it drew more current than my MRC6200 (which was supposedly 60 VA) could put out, and it could not spin the cleaning wheels fast enough either.
With heavily oxidized track, the cleaner must be set to move very slow such that the rail is pretty much perfect the first pass. I have seen many in use, and most people are too impatient to run it slow enough to clean the rails enough for it to move on it's own.
I gave up on track cleaning and went stainless steel and never looked back.